Formation of periodontal pocket by cadmium exposure - Induction of KGF by cadmium in tobacco -

在含Cd的培养液中培养人牙龈成纤维细胞(GF细胞)和牙周角质形成细胞(GK细胞)，并用四甲基偶氮唑盐(MTT)比色法和DNA合成方法评价Cd对细胞的影响，以研究Cd对牙周成纤维细胞和牙周角质形成细胞的镉敏感性。四甲基偶氮唑盐比色法检测结果显示，各剂量组(10 mm~10 mm)与对照组相比，两种细胞类型均无明显差异。当Cd浓度在10~(-6)mM及以上时，DNA合成受到抑制，尽管两种细胞的抑制程度不同。在上述条件下，当Cd浓度为10~(-3)~(-3)mM时，对GF细胞产生IL-6和IL-8，而对GK细胞则有轻微的抑制作用。这一结果表明，GF细胞和GK细胞对Cd有不同的细胞反应。相反，在GK细胞中没有观察到上述细胞因子在任何浓度下的诱导。这些结果表明，GF和GK细胞对Cd的细胞反应不同。在GF细胞中，10^lt；-2&gt；10^lt；-4&gt；mm Cd作用48小时，可诱导10%~20%的细胞发生凋亡。此外，还研究了Cd(10~(-3)mM)、IL-6(20 ng/m L)或内毒素(E.Coli，0.1g/m L)作用于GF细胞24小时对KGF-1产生的影响。对照组细胞中未检测到KGF-1的表达，而处理组细胞中可检测到KGF-1的表达。Cd组的浓度最高，其次是IL-6组，最后是内毒素组。根据以上结果，认为香烟中所含的Cd对牙龈细胞有损伤作用，并有助于牙周袋的形成。

The cadmium (Cd, as CdCl_2) sensitivity of human-derived gingival fibroblasts (GF cells) and gingival keratinocytes (GK cells) was studied by cultivating in media containing Cd, and assessing the effects of the Cd on the cells using an MTT assay and DNA synthesis. The results of the MTT assay revealed there were no clear differences between any of the Cd groups (10^<-8> mM to 10 mM) and the control group for either type of cell. DNA synthesis was inhibited at Cd concentrations of 10^<-6> mM and above, although there were differences in the degree of inhibition between the two types of cells. Under the above conditions, IL-6 and IL-8 were induced at a Cd concentration of 10^<-3> mM in GF cells, while in GK cells slight inhibition was observed. This result suggests that GF cells and GK cells have different cellular responses to Cd. In contrast to this, induction of the above cytokines was not observed at any Cd concentration in GK cells. These findings indicate that the cellular responses of GF and GK cells to Cd are different. In GF cells, it was found that apoptosis was induced in 10% to 20% of cells exposed to 10^<-2> to 10^<-4> mM Cd for 48 hours. The production of KGF-1 in GF cells exposed to Cd (10^<-3> mM), IL-6 (20 ng/mL), or LPS (E. coli, 0.1 g/mL) for 24 hours was also studied. KGF-1 could not be detected in control group cells, however, KGF-1 production was detected in treated cells. The highest concentration was observed in the Cd group, followed by the IL-6 group, and finally the LPS group.Based on the above results, it is believed that Cd contained in cigarettes injures gingival cells and contributes to the formation of periodontal pockets.